<template>
  <div :class="classes">
    <label :class="[prefixCls + '-label']" :style="labelStyles" v-if="label">
      <slot name="label">{{ label }}</slot>
    </label>
    <div :class="[prefixCls + '-content']" :style="contentStyles">
      <slot></slot>
      <transition name="fade">
        <div :class="[prefixCls + '-error-tip']" v-if="validateState === 'error' && showMessage && form.showMessage">
          {{ validateMessage }}
        </div>
      </transition>
    </div>
  </div>
</template>
<script>
  import AsyncValidator from 'async-validator';
  import Emitter from '../../mixins/emitter';

  const prefixCls = 'oolong-form-item';

  function getPropByPath(obj, path) {
    let tempObj = obj;
    path = path.replace(/\[(\w+)\]/g, '.$1');
    path = path.replace(/^\./, '');

    let keyArr = path.split('.');
    let i = 0;

    for (let len = keyArr.length; i < len - 1; ++i) {
      let key = keyArr[i];
      if (key in tempObj) {
        tempObj = tempObj[key];
      } else {
        throw new Error('[iView warn]: please transfer a valid prop path to form item!');
      }
    }
    return {
      o: tempObj,
      k: keyArr[i],
      v: tempObj[keyArr[i]]
    };
  }

  export default {
    name: 'oolongFormItem',
    mixins: [Emitter],
    props: {
      label: {
        type: String,
        default: ''
      },
      labelWidth: {
        type: Number
      },
      prop: {
        type: String
      },
      required: {
        type: Boolean,
        default: false
      },
      rules: {
        type: [Object, Array]
      },
      error: {
        type: String
      },
      validateStatus: {
        type: Boolean
      },
      showMessage: {
        type: Boolean,
        default: true
      }
    },
    data () {
      return {
        prefixCls: prefixCls,
        isRequired: false,
        validateState: '',
        validateMessage: '',
        validateDisabled: false,
        validator: {}
      };
    },
    watch: {
      error (val) {
        this.validateMessage = val;
        this.validateState = 'error';
      },
      validateStatus (val) {
        this.validateState = val;
      }
    },
    computed: {
      classes () {
        return [
          `${prefixCls}`,
          {
            [`${prefixCls}-required`]: this.required || this.isRequired,
            [`${prefixCls}-error`]: this.validateState === 'error',
            [`${prefixCls}-validating`]: this.validateState === 'validating'
          }
        ];
      },
      form() {
        let parent = this.$parent;
        while (parent.$options.name !== 'oolongForm') {
          parent = parent.$parent;
        }
        return parent;
      },
      fieldValue: {
        cache: false,
        get() {
          const model = this.form.model;
          if (!model || !this.prop) {
            return;
          }

          let path = this.prop;
          if (path.indexOf(':') !== -1) {
            path = path.replace(/:/, '.');
          }

          return getPropByPath(model, path).v;
        }
      },
      labelStyles () {
        let style = {};
        const labelWidth = this.labelWidth || this.form.labelWidth;
        if (labelWidth) {
          style.width = `${labelWidth}px`;
        }
        return style;
      },
      contentStyles () {
        let style = {};
        const labelWidth = this.labelWidth || this.form.labelWidth;
        if (labelWidth) {
          style.marginLeft = `${labelWidth}px`;
        }
        return style;
      }
    },
    methods: {
      getRules () {
        let formRules = this.form.rules;
        const selfRules = this.rules;

        formRules = formRules ? formRules[this.prop] : [];

        return [].concat(selfRules || formRules || []);
      },
      getFilteredRule (trigger) {
        const rules = this.getRules();

        return rules.filter(rule => !rule.trigger || rule.trigger.indexOf(trigger) !== -1);
      },
      validate(trigger, callback = function () {
      }) {
        const rules = this.getFilteredRule(trigger);
        if (!rules || rules.length === 0) {
          callback();
          return true;
        }

        this.validateState = 'validating';

        let descriptor = {};
        descriptor[this.prop] = rules;

        const validator = new AsyncValidator(descriptor);
        let model = {};

        model[this.prop] = this.fieldValue;

        validator.validate(model, {firstFields: true}, errors => {
          this.validateState = !errors ? 'success' : 'error';
          this.validateMessage = errors ? errors[0].message : '';

          callback(this.validateMessage);
        });
      },
      resetField () {
        this.validateState = '';
        this.validateMessage = '';

        let model = this.form.model;
        let value = this.fieldValue;
        let path = this.prop;
        if (path.indexOf(':') !== -1) {
          path = path.replace(/:/, '.');
        }

        let prop = getPropByPath(model, path);

//                if (Array.isArray(value) && value.length > 0) {
//                    this.validateDisabled = true;
//                    prop.o[prop.k] = [];
//                } else if (value !== this.initialValue) {
//                    this.validateDisabled = true;
//                    prop.o[prop.k] = this.initialValue;
//                }
        if (Array.isArray(value)) {
          this.validateDisabled = true;
          prop.o[prop.k] = [].concat(this.initialValue);
        } else {
          this.validateDisabled = true;
          prop.o[prop.k] = this.initialValue;
        }
      },
      onFieldBlur() {
        this.validate('blur');
      },
      onFieldChange() {
        if (this.validateDisabled) {
          this.validateDisabled = false;
          return;
        }

        this.validate('change');
      }
    },
    mounted () {
      if (this.prop) {
        this.dispatch('oolongForm', 'on-form-item-add', this);

        Object.defineProperty(this, 'initialValue', {
          value: this.fieldValue
        });

        let rules = this.getRules();
//                alert(rules.length);

        if (rules.length) {
          rules.every(rule => {
            if (rule.required) {
              this.isRequired = true;
              return false;
            }
          });
          this.$on('on-form-blur', this.onFieldBlur);
          this.$on('on-form-change', this.onFieldChange);
        }
      }
    },
    beforeDestroy () {
      this.dispatch('oolongForm', 'on-form-item-remove', this);
    }
  };
</script>
